Dental implants are used to anchor a mechanical fixture, such as a dental prosthesis, into living bone. The implant is embedded into the bone to provide a solid foundation for connecting the dental prosthesis. The implants and their respective dental prostheses serve numerous purposes, such as to assist the user with chewing, to provide a mating surface for an opposing tooth to prevent the loss of the opposing tooth, and to present an aesthetically pleasing appearance.
Prior to inserting the implant into the bone, the bone must be drilled to provide a recess for the insert to be implanted. Previously, implants were designed to be placed perpendicularly to the bone surface. The location of the implant in the user's mouth and the amount of mouth opening severely limit the ability to insert the head of the implant perpendicularly to the bone. Due to these limitations, most often, implants are inserted at an angle with respect to the bone surface. The angular insertion of an implant creates two problems: a) the mesial top portion of the implant is inserted too deeply into the bone, and, b) the distal top portion protrudes excessively from the bone. Furthermore, two problems arise at different stages of the treatment. The bone overgrows on the mesial aspect, thus requiring additional osseous surgery to remove excess bone. Later on, on the mesial aspect, the bone continues to resorb in order to accommodate biologic width. Biologic width is approximately 2 millimeters of connective tissue that wraps around a natural tooth or an implant and is constant. Violation of this area creates chronic inflammation and bone resorption.
To attempt to compensate for these problems, other prior art implants have been provided that disclose a top face that extends in a single plane oblique to a longitudinal axis of the implant. Such implants provide improved mechanical properties and anchorage but do not address biological fit, the implant exit and its relationship to the gum tissue. It would be beneficial to provide a dental implant having a top face with multiple slants. Slants on the mesiodistal aspect allow an angulated insertion of the top of the implant, having the top of the implant parallel to the bone surface and thus enabling a smooth development of biological width. The facial slant yields better aesthetic results due to the curved outline at the gum level.
A still further problem arises with implants after insertion into the mouth. Implants are threaded to secure the implant into the bone. The implants are axially symmetrical in order to enable such threading. Implants that are threaded and axially symmetrical do not anatomically fit the tooth roots, leaving a gap between the implant and bone in the coronal aspect, requiring significant time for healing. Such implants are prone to losing their primary stability, which is an important step in osseointegration. Osseointegration is the process by which the bone grows adjacent to the implant. Placement of an axially asymmetrical implant is less traumatic than the present rotational insertion method of an axially symmetric implant. It would be beneficial to provide an implant that is axially asymmetric and that fits the site of the extraction (body cavity) with little or no gap between implant and bone.